Computing apparatus



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Jan. 4, 1966 Filed sept. 14. 1960 Jan. 4, 1966 o. L. UTT ETAL.

COMPUTING APPARATUS 4 Sheets-Sheet 5 Filed Sept. 14, 1960 NNN Jan. 4, 1966 o. UTT ETAL 3,227,871

COMPUTING APPARATUS Filed Sept. 14, 1960 4 Sheets-Sheet 2 Il! III-III llllllllllllllllllllllllllll-Illll .IIIIIII Il III www Jan. 4, 1966 o. L. u'r'r ETAL 3,227,871

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United States Patent O 3,227,871 COMPUTING APPARATUS Orval L. Utt, Monroeville, and Richard D. Campbell,

Harmarville, Pa., assignors to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvanua Filed Sept. 14, 1960, Ser. No. 55,904 4 Claims. (Cl. 246-182) Our invention relates to computers, and particularly to l'computing apparatus for generating and storing an adjustable `average value signal derived as a function of a plurality of yselectively applied measured value signals.

In many control and computing systems in which the operation of the system is influenced by continuously or intermittently measured parameters, it is necessary or desirable to continue operation even though one or more of the measurements =of a given parameter may not be suited for use. In such a case, it would be desirable to have available an auxiliary value of the missing parameter, which is adjusted in accordance with each of the preceding acceptable measurements of that parameter, so as to represent substantially their average, and which may be substituted in the system at any time that a measurement is absent `or exhibits undesirable characteristics. Such a substitution would permit operation of the system to continue without any significant variation.

As -one specific example, in automatic railway classification yards it is the present practice to control the speeds of cars by the use of car retarders which exert a braking force in accordance with the measurements of several parameters which reflect the performance of the cars. The desired result `of such braking is to allow each car to roll to a gentle coupling in its classification track. One such automatic railway classification yard control system is shown and described in the copending application for Letters Patent of the United States of David P. Fitzsimmons (deceased) and William A. Robison, Jr., Serial No. 676,730, filed August 7, 1957, and assigned to the assignee of the present application.

In such a system, each car, following its uncoupling at the hump, rolls -over a stretch of tangent track in advance of the master retarder and its tangent track rolling resistance is measured and stored in an electronic circuit where it remains until the car passes through the master retarder and approaches a group retarder leading to the selected classification track destination. The value of rolling resistance registered for each car is then supplied along with other parameters to suitable speed control apparatus which continuously adjusts the brake pressure of the group retarder so that the desired leaving speed of the car from the group retarder is automatically obtained. It has been found that in such a system cuts of only one car will occupy the stretch `of tangent track for a time suiiicient to enable the car to become practically free rolling at the time its rolling resistance measurement is completed. Under these conditions, measured values `of rolling resistance obtained from the single cars are relatively true indications of the rollability yof the cars. However, since the practical length of the tangent track section in a classification yard is limited for various reasons, a multiple car cut rolling over the same stretch of track and under similar track conditions will generally not attain free rolling speed at the time the rolling resistance measurement is concluded, because the rear car of the cut may still be -occupying the relatively level track at the crest of the hump. Such measured values of rolling resistance, obtained when a cut is not free rolling, will therefore ordinarily be unreliable when determining the speed that a multiple car cut should leave the group re- 3,227,87i Patented Jan. 4, 1966 lCe tarder in order to couple safely with preceding cuts on its assigned classification track. It is, therefore, expedient to cancel out values of rolling resistance obtained from multiple car cuts and handle these cuts instead by utilizing an auxiliary signal which is continuously adjustable and which represents a running average of a plurality of rolling resi-stance signals derive-d in advance from preceding single car cuts, but only from Ithose single cars which exhibit values of rolling resistance known with a marked degree of certainty to be accurate, or valid.

Accordingly, where apparatus is provided for measuring the rolling resistance of multiple and single car cuts over tangent track, and apparatus is provided for generating and storing selectable average value of rolling resistance, the values of rolling resistance .obtained from multiple car cuts may be considered invalid for controlling their speeds, and for causing any change in the stored average value of rolling resistance selected for adjustment.

A particular object, therefore, of our invention is to provide, in conjunction with apparatus which produces such average value signals, means for distinguishing between multiple and single car cuts so as to selectively permit adjustment of the average value signals.

A more particular o'bject of our invention is to provide a plurality of average value signals of tangent track rolling resistance, one for each car weight group, whereby the weight information obtained from each multiple car cut will determine which one of the sto-red average Value signals will be used in the control of its speed.

Other objects, features and advantages yof -our invention will 'become apparent as the specification proceeds.

In practice, apparatus embodying our invention comprises rolling resistance measuring means, means for determining whether the rolling resistance signals obtained from all cuts satisfy or fail to satisfy certain predetermined criteria, means for generating and storing a plurality of the said 4average value signals, a car weight determining means for enabling the proper selection for adjustment of one of the several average value signals, axle detecting mean-s connected with a relay counting circuit for checking the number of axles in each cut to ascertain whether a cut comprises only `one or more than one car, and circuit means cooperating with the average value signal generating and storing means, and controlled by the relay counting circuit, for beginning the adjustment of the selected average value signal in accordance only with valid or acceptable measured value signals acquired from cuts o-f yonly -one car.

We shall describe a preferred form of apparatus ernbodying our invention, and shall then point out the novel features thereof in claims.

We have illustrated an embodiment of our invention which is adapted to be employed in a tangent track rolling resistance measuring system of the type disclosed in the above-referred to copending application. Only those components of the system disclosed in said copending application which are necessary to make the disclosure complete and to an understanding of our invention have been illustrated, and in most instances these components have been illustrated in block diagram form. However, the correspondence between schematically illustrated components and those shown in the above-mentioned copending application will be readily apparent as the description proceeds.

Furthermore, in order to simplify the illustration of the circuit employed in our invention, the necessary power supply is shown conventionally as a source of voltage, such as a battery, having positive and negative terminals, connections to which are schematically indicated on the drawings by the reference characters B and N, respectively,

3 associated with arrow symbols indicating connections to the battery terminals.

In practice, tangent track rolling resistance is usually measured in pounds per ton, that is, the frictional force in pounds force opposing the motion of the car per ton of weight supported by the wheels of the car. For convenience, tangent track rolling resistance hereinafter may be referred to as Rt, and it will be understood that Rt may in a particular case be represented either by an average value signal or a measured value signal.

In the accompanying drawings:

FIGS. la, 1b and 1c, when placed side by side in the order named, with FIG. la at the left, are diagrammatic views showing one form of apparatus embodying our invention.

FIG. 2 is a chart showing the sequence of operation of the relays used in the embodiment of our invention shown in FIG. 1c.

In the drawings, the reference characters 1a and 1b designate the track rails of a stretch of track down which cars move under gravity from a hump to storage tracks, not shown, in the direction indicated by the arrow adjacent the track in FIG. la. These track rails are divided by insulated joints 2 into a track section designated AT and two car retarder sections MRlT and MRZT, placed end to end to be traversed by cars in that order. Track sections AT, MR1T, and MR2T are provided with track circuits including sources of track circuit energy designated ATB, MRlTB, and MRZTB, respectively, the rails of the respective track sections, and track relays ATR, 1TP, and 2TP, respectively. Relays ATR, 1TP, and ZTP are arranged in a manner well known in the art to become energized when their respective track sections are unoccupied and deenergized when their respective rtack sections are occupied.

An end-of-cut relay GEC (Fig. lc) is provided for indicating the moment the rear wheels of a cut of cars vacate track section MRIT, for a purpose which will be made clear hereinafter. Specifically, relay GEC has an energizing circuit which may be traced from terminal B of the battery over front contact a of relay 1TP, wire 174, back contact a of relay 2TP, wire 176, and the winding of relay GEC to terminal N of the battery. It is believed sufficiently clear from the above description of the operation of relays ITP and ZTP that relay GEC will become energized only when section MR1T is vacant and section MRZT is occupied, and will become deenergized when section MRZT is vacated.

Referring now to FIG. la, we have shown in block diagram form a radar velocity meter whose input terminal a is connected to an antenna 12 located adjacent track section AT, and whose output terminal b is connected to the input terminal a of a differentiator 14. Velocity meter 10 supplies a velocity signal to difierentiator 14 lwhich in turn supplies from its output terminal b an acceleration signal to input terminal a of bias unit 16. For the details of the structure and operation of the radar velocity meter, the diiterentiator and the bias unit, reference is made to the above-mentioned copending application Serial No. 676,730. Since these units form no part of our invention, it is sufiicient for the purposes of this description to point out that the output from terminal b of bias unit 16 is representative of the tangent track rolling resistance measurements to be utilized by the apparatus of our invention. These measurements are proportional to the acceleration of cars moving in the path of antenna 12 of velocity meter 10.

As described in detail in copending application Serial No. 676,730, the output signal at terminal b of bias unit 16 may be applied to input terminal a of a primary electronic storage unit 18 of the type shown in FIG. la, over a circuit which includes back contact a of relay ATR, when the rails of section AT are shunted, and wire 20. The details of such a storage unit are fully described in Letters Patent of the United States No. 2,914,750, issued November 24, 1959, to James A. Cook, Jr., for au Electronic Storage Device, and assigned to the assignee of our present invention.

Brieiiy, however, as shown, electronic storage unit 18 comprises a primary storage relay herein designated PSR and a D.C. amplifier 24 having an input between terminal a and ground terminal b and an output between terminal c and ground terminal a'.

As described in Patent 2,914,7150 the signal to be stored is applied to terminal a of storage unit 18 and thence through a resistor 26, back contact f of relay PSR, a capacitor C1, back contact g of relay PSR, and lthrough a `resistor 28 to ground. In the conditi-on shown, output terminal c of amplifier 24 is connected over back contact a' of relay PSR and through resistor `28 to ground to provide a first feedback circuit to the amplifier. Resistor 28 is thus connected in shunt with the input and output circuits of the amplifier. With relay PSR deenergized, the applied signal causes current to flow through resistor 26, capacitor C1, and resistor 28 in series. While the capacitor is charged, the input and output circuits of amplifier 24 are connected together and shunted by resistor 28. Accordingly, a voltage will be developed at the output of the amplifier in accordance with the internal characteristics of the amplifier. This voltage will appear across resistor 28. The polarity of this voltage may be equal or opposite to that provided by the applied signal. If the voltages are opposite in polarity, capacitor C1 will be charged to a voltage equal to the sum between the applied signal voltage and the voltage developed by the amplifier across resistor 28. If .the voltages are of the same lpolarity, the capacitor will be charged to a voltage equal to the ditlerence of the applied signal and the voltage across resistor 28. In either case, the capacitor is charged to a voltage which diiers from the voltage supplied to terminal a of unit 18 by the voltage developed across resistor 28.

The circuit constants are so chosen that capacitor C1 is charged rapidly. When relay PSR is energized, the connection between the amplifier output circuit and the input circuit is interrupted lat the open back contact d of relay PSR. The circuit for resistor 28 is also open at back contact g of relay PSR, while back contact f opens the charging circuit for capacitor C1. The closing of front contact e of re-lay PSR now connects a resistor 30 in series with capacitor C1 in the feedback circuit between input terminal a -and output terminal c of ampliiier 24. A high value is chosen for resistor 30, and since the amplifier is arranged to have negligible current flowing in the input circuit, capacitor C1 lretains its charge for a relatively long period of time during which the stored value of the applied signa-l is available between terminal c of unit 18 and ground terminal d of ampliiier 24.

The signal appearing at output terminal b of bias unit 16 and applied to 'back contact a of relay ATR when section AT is occupied is Iapplied over a parallel path including wire 32 to input terminal a of a validity detector 34 for evaluating the integrity of a signal. Validity detector 34 may be of the type shown and described in the copending application for Letters Patent of the United States Serial No. 809,191, filed April 27, 1959 by I ames A. Cook, Ir., for la Validity Detector, assigned to the assignee of our present invention and now Patent No. 3,091,688, issued May 28, 1963.

For a complete description and full understanding of the operation of validity detector 34, reference is made to this Cook Patent No. 3,091,688 which discloses (FIG. 1b) a relay whose designation corresponds to the relay VR shown in the present application, .and whose energization is delayed until it has been established that the measured rolling resistance signal is stable and within prescribed limits. For present purposes, therefore,

it is believed suicient to note that relay VR will remain deenergized unless the rolling resistance signal applied to its input terminal cz satises the predetermined criteria. Accordingly, with relay VR energized, it closes its front contact a, thus energizing relay yPSR over a circuit which may be traced from terminal B of the battery over front contact a of relay VR, wire 36, back c-ont-act c of relay GEC, wire 38, back contact b of counting circuit relay R1 (described later), wire 179, te-rminal b of storage unit 18, and through the winding of relay PSR to terminal N ofthe battery. Although relay VR may become deenergized before the .intended control operation of our system is completed, relay PSR is held energized over a stick circuit which will be subsequently traced. Therefore, with the energization of relay VR, storage of the signal in unit 18 is complete, and the stored signal may thereafter be read out of unit 18.

There is also shown in FIG. la, and designated as a whole by the reference character 40, a weight determining unit which Iincludes two weight repeater relays RHP `and RLP. Unit 48 corresponds to a similar unit shown in Letters Patent of the United States No. 2,819,682 of Edward C. Falkowski for Car Retarder Speed Control Apparatus. For a detailed description of t-he weight determining unit, reference is made yto Patent No. 2,819,- 682; however, a brief description of the operation of this unit will now be given.

Unit 40, -as shown herein, includes a weight responsive contact member 42 having a mechanical connection schematically indicated at 44 to rail 1b for operation in response to the deflection of the rail as a car wheel rolls over the rail at the point of connection. Contact member 42 is biased by Va spring 46 to an upper or open position, that is, -to the posit-ion shown in the drawing. Deflection of the track rail under the Weight of a wheel forces contact member 42 downward against the force of spring 46, the member 42 constantly engaging a stationary contact 47 and selectively engaging stationary contacts 48, 49 and 50 according to the deflection of the track rail. In operation, contact member 42 is forced downwardly so that only contact 47-48 is closed for light weight cars (-less than 40 tons), both contacts 47-48 and 47-49 are closed for medium weight cars (between 40 land 60 tons), and all three contacts 47-48, 47-49 and 47-50 lare closed for heavy weight cars (over 60 tons). Obviously, contact 47-48 will be closed eac-h time a wheel, or an axle 4of la car, rol-ls over the location of unit 40; and, therefore, it can serve as an axle counter, as will be described more completely hereinafter.

Unit 4@ also comprises a pair of weight repeater relays RLP and RHP, as shown. Since the details of the weighing unit form no part of our present invention, the circuits for controlling these relays in response to the actuation of contacts 48, 49 and 58 are not shown. It is sufficient for an understanding of our invention to note that, as described in Patent No. 2,819,682, weight repeater relays RHP and RLP are energized `in three different combinations. For cars in the light weight group, relay RLP becomes energized and relay RHP remains deenergized; for a cut ot cars in the medium weight group, both relays RHP and RLP become energized; and for cuts of cars lin the heavy weight group, relay RHP becomes energized and relay RLP remains deenergized.

Output terminal c of storage unit 18 is connected by means of wire 52 to input terminal a of a generator and storage unit provi-ded for producing a plurality of adjustable average value signals of Rt, which unit is designated as a whole by the reference character 54, Iand shown substantially complete in FIG. 1b of the drawings. Such a unit is essentially identical to the one described in our copending application for Letters Patent of the United States, Serial No. 802,450, led March 27, 1959, for Computing Apparatus, having the same assignee as the present invention and now Patent No. 2,977,462, issued March 28, 1961. Since this apparatus is described in detail in this issued patent, it will not be fully described here. Briefly, however, `as illustrated in our presen-t invention, generator and storage unit 54 comprises, from left to right in lFIG. 1b, resistors 56 and `58, a secondary electronic storage unit 60 including a secondary storage relay SSR whose energizing circuit will -subsequently be traced, a difference amplifier 62, a diierential relay unit 64 including a diierential relay DR, and a group of contacts -controlled yby the previously-mentioned weight repeater relays RHP and RLP. Unit 54 further comprises three potentiometers 66, 68 and 70 for storing average value signals of Rt for use by car cuts in the heavy, medium, and light weight groups, respectively, as will -be described. Servomotors 72, 74 and `'76 are drivably connected to the Wipers of potentiometer-s 66, 68 and 70, respectively, for adjusting the wiper of a selected one of the potentiometers to provide a continuous or running average value of Rt in the selected potentiometer. The Servomotors are preferably of the type known in the art as reversible motors, in which the direction of rotation of the output shaft depends upon the direction of current owing through the armature of the motor. The mechanical connection between the output shaft of each servomotor and the wiper of the potentiometer controlled thereby is shown in the conventional manner by a da-shed line. The parts comprising the generator and storage unit 54 as shown herein will rst 'be described, and their operation for averaging successive measured value signals of Rt will then be described.

Thus, in the present application, resistors S6 and 58 correspond respectively to resistors R1 and R2 shown in FIG. 2 of our prior Patent 2,977,462I and together comprise a conventional summing circuit used to obtain an output voltage at their common junction proportional to the sum of voltages at their input ends. Resistor 56 is connected at one end to input terminal a of -unit l54 and at its other end is connected with one end of resistor 58 Ito form the common junction therewith. The other end of resistor `58 is connected over a rst path including wires 78 and 80 to front contact b of relay SSR, and over a second path including wires 78 and -82 to the heel of contacts c and d of relay RHP.

The common junction of resistors 56 and 58 is connected to input terminal a of storage unit 60, which unit, as shown, is provided with an output terminal b and grounded input and output terminals c and d, respectively. The operation of storage unit 60 is identical to the operation of the aforementioned primary storage unit 18 shown -in FIG. la. 'For present purposes, therefore, it is kbelieved suicient to point out that the signal to be store-d is applied between terminal a and ground terminal c. When it is desired to complete the storage, relay SSR is energized from terminal B of the battery over external circuitry to =be described and through the winding of relay SSR to terminal N of the battery. The stored voltage may then be read out of the unit between output terminal b and ground terminal d.

Difference amplier 62 is provided with a iirst input terminal a connected with output terminal b of secondary storage unit 60; a second input terminal b which may be connected with the heel of contact b of relay SSR; and a grounded terminal c on its input side. The output signal of amplier 62 appears between its two output terminals d and e.

Difference amplier 62 may be of a conventional type well known in the art, which provides 'between its output terminals a signal which is proportional to the difference between signals simultaneously applied to its input terminals. Generally, with signals of difr'erent amplitudes applied to its input terminals, the amplier is said to Abe unbalanced. In laccordance with operating characteristics of amplifier 62, it is possible, by applying a -substantially constant signal to one of its input terminals,

and at the same time applying a changing signal to its other input terminal, to obtain 4at certain times between its output terminals a signal which diminishes ltoward zero as lthe difference between the input signals becomes smaller. Under these conditions, when practically no difference exists between the signals at terminals d and e of amplifier 62, the amplifier is said to be balanced.

The output terminals d and e of difference amplifier 62 are coupled to input terminals a and b, respectively, of a differential relay unit 64 comprising a differential relay DR of a conventional type well known in the artt. Relay DR, as herein shown, comprises two normally deenergized windings 88 and 90 having a common conneetion at one end to the positive terminal of a 'battery 92' which provides the supply voltage for amplifier 62. The negative terminal of battery 92 i-s directly connected to terminal c of unit 64 and may be traced therefrom to ground over a circuit including front cont-act c of relay SSR. Operation of amplifier 62 and any consequent actuation of relay DR can occur only, therefore, when relay SSR 'becomes energized'.

Output terminals d and e of differential relay unit 64 are connected through the winding of a relay R9 which may be energized from one or the other of two circuits, depending upon which winding of relay DR is energized at a particular time. The energizing circuits for relay R9 will be described shortly.

As schematically indicated, the armature controlled by relay DR iscommon to contacts a, b, andd of relay DR. When windings 88 and 90 are both deenergized, the armature is normally in its neutral position wherein the contacts are in their open positions, as shown. When relay DR is operated, the winding through which the greater current is initially flowing will operate to close one pair of its contacts, whereas theother pair of contacts will remain open. By way of illustration, if the output voltage initially appearing at output terminal d of amplier 62 is greater than the voltage appearing at the other output terminal e, winding 88 will become energized to a greater degree than the other winding 90, and contacts a and b of relay DR will move to their closed position, whereas contacts c and d will remain in their open position. A first energizing circuit for relay R9 may now be traced from terminal B of the battery, over Contact a controlled by winding 88, wires 116 and 118, terminal d of unit 64, through the winding of relay R9, terminal e of unit 64, wire 124, and over contact b controlled by winding 88 to terminal N of the battery. On the other hand, if the output voltage appearing at terminal d of amplifier 62 is initially less than the voltage appearing at its other output terminal, winding 90 Will become energized to a greater degree than winding 88, and contacts c and d will move to their closed positions, whereas contacts a and b will remain in their open positions. A second circuit for energizing relay R9 :may now be traced from terminal B of the battery, over contact d controlled by winding 90, wire 124, from output terminal e of unit 64 through the winding of relay R9 to the other output terminal d, wire 118, and over contact c controlled by Winding 90 to terminal N of the battery. When amplifier 62 reaches its balanced condition, as hereinabove described, the ux in windings 88 and 90 will become neutralized, causing the armature of relay DR to assume its neutral position. At this time, the contacts controlled by the winding having the initially greater energization will be returned to the positions in which they are shown in the drawing. As a consequence thereof, the energizing circuits for relay R9 will be interrupted. It will thus be apparent that relay R9 is deenergized in the balanced conresistor 58V over wire 100, back contact d of relay RLP, front Contact c of relay RHP, and wires 82 and 78.

Potentiometer 68 may have one end of its resistive element connected to the negative terminal of battery 94 through wire 98, the other end of the resistive element being connected to ground. The wiper of potentiometer 68 is at times connected to the lower end of resistor 58 over wire 102, front contacts e and c, respectively, of relays RLP and RHP, and wires 82 and 78.

One end of the resistive element of potentiometer 70 is connected to the negative terminal of battery 94, the other end of the resistive element having a connection with ground. The wiper of potentiometer 70 is at times connected to the lower end of resistor 58 over wire 104, front contact f of relay RLP, back contact d of relay RHP, and wires 82 and 78.

The operation of the generator and storage unit 54 in response to a valid measured value signal of Rt applied thereto for a cut in, for example, the heavy weight group will now be described. First, it will be recalled that the voltage appearing at input terminal a of unit 54 and hence applied to one end of resistor 56 represents an actual or measured value signal of Rt of the cut'. Further, only relay RHP of the weight repeater relays will become energized so that the wiper voltage of potentiometer 66 will be applied to the lower end of resistor 58 over the abovetraced circuit. A composite voltage will therefore appear at the common junction of resistors 56 and 58 and is applied to input terminal a of unit 60. As pointed out in our prior patent, the voltage thus fed to unit 60 is proportional to the sum of the voltage at the wiper of potentiometer 66 plus a preselected percentage of the difference between this wiper voltage and the voltage applied to terminal a of unit 54. This preselected percentage may be any selected value, but is preferably identical to the figure established in our prior patent. The percentage is determined by resistors 56 and 58, and is equal to the ratio of resistor 56 to the sum of resistors 56 and 58, the values of these resistors being preferably so chosen that the indicated ratio is equal to approximately .1l or eleven percent. In other words, the value of the composite rolling resistance signal in the present embodiment differs from a particular selected average value signal by an amount equal to approximately eleven percent of the difference between that selected average signal and a measured value signal.

Thus, assuming relay SSR to be energized, the stored voltage of unit 60 is applied to input terminal a of amplifier 62. At the same time, the closing of front contact b of relay SSR will connect the other input terminal b of amplifier 62 to the wiper of potentiometer 66. The negative terminal of battery 92 will become grounded upon the closing of contact c of relay SSR. The output signal of amplifier 62 will be proportional to the difference between its two input voltages. It will now be assumed that the unbalanced output of amplifier 62 is such that the signal at output terminal d is greater than the signal at output terminal e. Accordingly, winding 88 of relay DR will become energized.

With winding 88 energized, relay R9 becomes energized over its previously traced first energizing circuit and completes a stick circuit for relay SSR which extends from terminal B of the battery, over front contact a of relay R9, wire 112, front contact a of relay SSR, wire 114, terminal e of storage unit 60, and through the winding of relay SSR to terminal N of the battery. Also, the armature of servomotor 72 is connected across the terminals of the battery over a circuit which may be traced from terminal B of the battery, contact a controlled by winding 88, wires 116 and 118, terminal d of unit 64, Wire 120, the armature of servomotor 72 in one direction, back contact a of relay RLP, front contact a of relay RHP, wire 122, terminal e of unit 64, wire 124, and over contact b controlled by winding 88 to terminal N of the battery. Servomotor 72 will accordingly become energized, and the positioning of the wiper of potentiometer 66 will now take place. Eventually, following adjustment of the Wiper, the voltages at input terminals a and b of amplier 62 will become substantially equal, thereby placing the amplier in its balanced condition. Winding 88 will accordingly become deenergized and return contacts a and b to their normal or open positions. The opening of contacts a and b will interrupt the energizing circuit for servomotor 72, and simultaneously effeet deenergization of relay R9 whereby the above-traced stick circuit for relay SSR will open. Relay SSR will accordingly become deenergized. Under these conditions, storage unit 60 is placed in a condition for storing a subsequent voltage applied thereto, and the wiper of potentiometer 66 is set to a new position above ground an amount substantially equal to the aforementioned preseiected dilerence between the signals applied to the input terminals a and b of amplifier 62.

Again, for cuts in the heavy weight group, and assuming now that winding 98 initially becomes energized, the armature of servomotor 72 will be connected across the battery through a circuit extending from terminal B of the battery, contact d controlled by winding 90, wire 124, terminal e of unit 64, wire 122, front contact a of relay RHP, back contact a of relay RLP, the armature of servornotor 72 in a reverse direction with respect to the above-traced path just described, wire 120, output terminal d of unitl 64, wire 118, and contact c controlled by winding 9i) to terminal N of the battery. The above-traced stick circuit for relay SSR is again completed due to the energization of relay R9 over its above-traced second energizing circuit. With servomotor 72 now energized in the reverse direction, the wiper of potentiometer 66 will be adjusted in a corresponding direction in a manner substantially as described above. It is believed suiliciently clear from the above description and drawings that when the adjustment of the wiper of potentiometer 66 is completed, winding 90 will become deenergized, thereby effecting deenergization of relay R9 and consequently causing the deenergization of relay SSR due to the interruption of its stick circuit. Servomotor 72 also becomes deenergized at this time.

It is particularly pointed out that, in the case where the measured value signal or Rt is greater than the average signal stored for cuts in the weight group to which that particular cut belongs, it is desired to allow the average value signal to follow the measured one, that is, to be increased. Under such conditions, servomotor 72 is preferably arranged to adjust the wiper of potentiometer 66 so that an increased voltage appearing between the wiper and ground will result. On the other hand, for conditions in which the measured value signal of Rt is less than the average value signal, servomotor 72 will preferably position the wiper of potentiometer 66 to decrease the voltage appearing thereat with respect to ground. In either case, the voltage level at the wiper will be adjusted in accordance with the direction of current through the armature of servomotor 72.

In a similar manner, servomotors 74 and 76 may operate to increase or decrease the output voltage appearing at the wipers of potentiometers 68 and 70 in response to measured values of Rt of cuts in the medium and light weight groups, respectively. It is believed sufficiently clear from the above description and the drawings that the forward and reverse energizing circuits for servomotor 74 may extend over the above-traced circuits for servomotor 72 including the contacts a, b, c, and d of relay DR, but will instead include front contacts b and a of relays RLP and RHP, respectively. Similarly, the energizing circuits for servomotor 76 will also include the contacts a, b, c, and d of relay DR, but will instead include front contact c of relay RLP and back contact b of relay RHP.

Referring now to FIG. 1c of the drawings, the operation of the relay counting circuit for distinguishing between 10 multiple and single car cuts, and allowing adjustment of a selected one of the average value signals of Rt in response only to signals obtained from single car cuts, will now be described.

The relays of the counting circuit concerned in the operation to be described include relays R1, R2, R3, R4, R5, R6, R7, and R8, all of which are normally deenergized, their contacts being shown in the positions they normally assume when the track is vacant. At this time relay ATR is energized over its above-traced track circuit.

Relay R1 has an energizing circuit extending from terminal B of the battery, over front contact a of relay R5, wire 125, front contact a of relay R8, wires 126 and 127, and through the winding of relay R1 to terminal N of the battery. Relay R1 has a stick circuit extending from terminal B of the battery, over back contact a of relay GEC, wire 139, its own front contact a, wire 127, and through the winding of relay R1 to terminal N of the battery.

Relay R2 has an enrgizing circuit extending from terminal B of the battery, over contact 47-48 of weight determining unit 48, terminal a of unit 40, wire 132, back contact c of relay R1, and through the winding of relay R2 to terminal N of the battery. It is pointed out that with relay R1 in its normal condition, relay R2 will become energized for each closure of contact 47-48.

Relay R3 has an energizing circuit extending from terminal B of the battery, over back contact d of relay R1, wires 134 and 136, front contact a of relay R2, back contact a of relay R4, wire 138, and through the winding of relay R3 to terminal N of the battery. Relay R3 has a stick circuit extending from terminal B of the battery, over back contact d -of relay R1, wires 134 and 136, back Contact b of relay R2, its own front contact a, wire 138, and through the winding of relay R3 to terminal N of the battery.

Relay R4 is provided with an energizing circuit extending from terminal B of the battery, over back Contact d of relay R1, wire 134, back contact d of rel-ay R2, front contact b of relay R3, Wire 140, and through the Winding of relay R4 to terminal N of the battery. Relay R4 has a stick circuit extending from terminal B of the battery, over back contact d of relay R1, wire 134, front contact c of relay R2, its own front contact b, and through the Winding of relay R4 to terminal N of the battery.

Relay R5 has an energizing circuit which extends from terminal B of the battery, over back contact d of relay R1, wire 144, front contact c of relay R4, front contact e of relay R2, wire 146, and through the winding of relay R5 to terminal N of the battery.

Relay R6 is provided with an energizing circuit which extends from terminal B of the battery, over front contact b of relay R5, wires 147 and 148, back contact a of relay R7, wire 149, back contact b of relay RS, and through the winding of relay R6 to terminal N of the battery. Relay R6 has a rst stick circuit extending from terminal B of the battery over its own front contact c, wire 150, front contact b of relay PSR (FIG. la), wires 152 and 148, back contact a of relay R7, Wire 149, back contact b of relay R8, and through the winding of relay R6 to terminal N of the battery. A second stick circuit is similar but substitutes a path through wire 147, back contact c of relay R5, and wire 154 for the path through Wire 148 and back contacta of relay R7.

Relay R7 has an energizing circuit extending from terminal B of the battery over back contact d of relay R5, wire 156, front Contact a of relay R6, wires 158 and 160, back contact d of relay SSR, wires 162 and 164, and through the winding of relay R7 to terminal N of the battery. Relay R7 has a first stick circuit extending from terminal B of the battery over its own front contact b, wire 166, back contact c of relay R8, wires 168, 158 and 160, back cont-act d of relay SSR, wires 162 and 164, and through the winding of relay R7 to terminal N of the battery. Relay R7 has a second stick circuit extending from terminal B of the battery, its own front contact b, wire 169, back contact e of relay R5, wire 169, back contact d of relay SSR, wires 162 and 164, and through the winding of relay R7 to terminal N of the battery. Relay R7 s provided with a shunt circuit which comprises a resistor 167 and a capacitor 171 series connected across the winding, which shunt circuit provides a time delay for its deenergization, and for a purpose which will be made clear hereinbelow.

Relay R3 has -an energizing circuit extending from terminal B of the battery over back contact g of relay R5, back Contact b of relay R6, front Contact c of relay R7, wire 170, and the winding of relay R8 to terminal N of the battery. Relay RS has a first stick circuit extending from terminal B of the battery over front Contact e of relay SSR (FIG. 1b), wires 172 and 173, its own front contact d, wire 17), and through the winding of relay R8 to terminal N of the battery. Relay R8 has a second stick circuit extending from terminal B of the battery over front contact f of relay R5, wire 173, its own front contact d, wire 170, and through the winding of relay R8 to terminal N of the battery.

A first stick circuit for relay PSR may be traced from terminal B of the battery, over front contact a of relay PSR, wire 178, back contact e of relay RS, wire 38, back Contact b of relay R1, wire 179, terminal b of unit 18, and through the winding of relay PSR to terminal N of the battery. Relay PSR is thus provided with a stick circuit immediately following its energization and becomes independent of the operation of relay VR of validity detector 34. As a result, the measured value signal of Rt is supplied from terminal c of unit 18 to input terminal a of unit 54 as long as relay PSR is energized.

It will now be assumed that a cut comprising only a single car rolls down the hump. As the car enters track section AT, its wheels and yaxles shunt relay ATR causing it -to become deenergized and thereby close its back contact a. With relay ATR deenergized, and with the car rolling in section AT in the path of antenna 12 of radar velocity meter 10, a signal equivalent to the rolling resistance of the cut is continuously developed and applied to input terminal a of validity detector 34. The Rt signal of the cut is simultaneously applied to terminal a of electronic storage unit 1S, thus causing condenser C1 to become charged in the manner described hereinabove. It will further be assumed that the cut exhibits a valid measured value signal of Rt so that relay VR of detector 34 becomes energized. With relay VR energized, the abovetraced pickup circuit for relay PSR is completed and relay PSR accordingly becomes energized. With the closing of front contact a of relay PSR, its first stick circuit is closed. Storage of the measured value signal of Rt of the car is thus completed, and the stored signal is made available to input terminal a of unit 54 and one end of resistor 56.

As the cut proceeds farther down the hump, but prior to the time it enters the first retarder section MR1T, the weight group of the cut is determined by the weight determining unit 40, which, as hereinabove mentioned, is adjusted -so that the Contact 47-48 is closed each time the wheel of a car in any of the weight groups passes over it. It will be assumed that the cut is classified in the heavy weight group, so that relay RHP becomes energized. With relay RHP energized, the wiper of potentiometer 66 will be connected with the lower end of resistor 58 over the circuit previously trace-d. The input ends of resistors 56 and 58 are now respectively supplied with measured and average value signals of Rt. The composite rolling resistance is applied to input terminal a of unit 60 and will be stored therein upon the energization of relay SSR. As will now be described, counting is accomplished by detecting the number of times that Contact 47-48 is closed prior to the time relay GEC becomes energized.

When the first pair of wheels, or the first axle of the car, passes over the location of unit 40, contact 47-48 is closed, thereby completing the above-traced pickup circuit for relay R2. Relay R2 becomes energized and closes its front contact a to complete the above-traced pickup circuit for relay R3. Relay R3 accordingly becomes energized and closes its front contact a. When the first wheel releases contact member 42 of unit 40, contact 47-48 reopens to interrupt the pickup circuit for relay R2 and causes it to become deenergized. The energizing circuit for relay R3 therefore becomes open at front contact a of relay R2. Relay R3, however, is of the slow release type, as indicated, to delay its release and allows relay R2 to close its back contact b to complete the stick circuit for relay R3 before relay R3 can release its front contact a. With front contact b of relay R3 held up, and back contact d of relay R2 now closed, the above-traced energizing circuit for relay R4 is completed, thereby causing this relay to become energized. Relays R3 and R4 will accordingly remain energized during the time required for the second wheel of the car to reach unit 4t). Relay R2 will be in its normal or deenergized condition.

The incidence of the second wheel of the car on contact member 42 will again close contact 47-48, and relay R2 will become reenergized. With relay R2 energized for the second time, the above-traced stick circuit for relay R3 is interrupted at back contact b of relay R2 causing relay R3 to become deenergized and shortly release. At the same time, the above-traced stick circuit for relay R4 will be completed at front contact c of relay R2. Thus, during the time the second wheel is being weighed, relay R5 becomes energized over its above-traced circuit including front contact c of relay R4, front Contact e of relay R2, and back Contact d of relay R1.

Relay R5 thus energized indicates that the wheel on the second axle of the car is presently actuating contact member 42 of unit 4f). Relay R6 becomes energized over its previously-traced circuit including front contact b of relay R5, back contact a of relay R7, and back contact b of relay R8.

The departure of the second wheel of the car from unit 40 results in relay R2 becoming deenergized, due to the fact that contact 47-48 of unit 4t) reopens. Accordingly, the above-traced stick circuit for relay R4 including front contact c of relay R2 is opened to cause relay R4 to release its contacts. Obviously, with either relay R2 or R4 deenergized, relay RS becomes deenergized. It will be appreciated, therefore, that relay R5 becomes energized once for every two times relay R2 responds to the closing of contact 47-48. That is, relay R5 will operate as even-numbered wheels of a cut act upon weight determining unit 40.

Upon relay R5 becoming deenergized, relay R6 will be held up over its previously traced stick circuit including its own front contact c, front contact b of relay PSR, back contact c of relay R5, and back contact b of relay RS. At the same time, due to the deenergization of relay RS, relay R7 is energized over its previously traced pickup circuit, including back contact d of relay R5, front Contact a of relay R6, and back contact d of relay SSR. Relay R7 is held energized over its above-traced first stick circuit including its own front contact b, back contact c of relay R8, and back contact d of relay SSR.

Immediately upon relay R7 becoming energized, a second stick circuit for relay PSR is now completed and extends from terminal B of the battery, over front contact a of relay PSR, Wire 178, front Contact e of relay R7, back contact b of relay R1, wire 179, terminal b of storage unit 1S, and through the winding of relay PSR to terminal N of the battery.

Thus, subsequent to the second wheel of the car leaving the location of unit 4t), but prior to the arrival of the third Wheel, relays R2, R3, R4, R5 and R8 are in their 13 normal or deenergized conditions, and relays R6, R7 and PSR remain energized over their respective stick circuits. With this portion of the counting sequence completed, the first two axles of the car have cleared the weight determining unit.

In a manner similar to the operation for detecting the first two axles of the car, relay R2 will become energized in response to the wheel on the third axle depressing contact member 42, and will again become energized due t the action of the Wheel on the fourth axle. Also, as before, while the load on the fourth axle is being weighed, a circuit is completed through the above-traced path for energizing relay R for the second time. Further, as before, relay R5 remains energized only during the time that the wheel on the fourth axle is being weighed; or, in other words, while relay R2 is energized.

Due to relay R5 becoming energized for the second time, its back contact c will open and interrupt the previously-traced stick circuit for relay R5. Since the pickup circuit, and the other stick circuit, for relay R6 are already open at back contact a of relay R7, relay R6 becomes deenergized and releases.

As soon as the fourth wheel of the car leaves contact member 42, relay R5 will again become deenergized, as described hereinabove in connection with the passage of the second wheel. At this time, due to relays R6 and R7 being deenergized and energized, respectively, relay R3 becomes energized over the previously-traced circuit including back contact g of relay R5, back contact b of relay R6, and front contact c of relay R7. With relay R8 now energized, the above-traced first stick circuit for relay R7 is interrupted at back contact c of relay R8. Relay R7 will, however, remain energized over its previously-traced second stick circuit which includes its own front contact b, back contact e of relay R5, back contact d of relay SSR, and its own winding. Also, the abovetraced first stick circuit for relay PSR is interrupted at contact e of relay R8. It will be realized, however, that the second stick circuit of storage relay PSR remains closed over front contact e of relay R7. The circuit of storage unit 18 continues to render the stored signal available.

Thus, as best can be seen in FIG. 2, as the fourth wheel of the car moves to the down-grade side of weight determining unit et?, relays R2 through R6 will have been restored to their normal conditions. Relays R7, R8, and PSR are energized over their respective circuits.

As the car continues down grade, relay GEC becomes energized over its above-traced circuit, as previously described. At this time, due to relay GEC becoming energized, relay SSR also becomes energized over a pickup circuit extending from terminal B of the battery, over front contact b of relay GEC, wire 180, front contact c of relay PSR, wire 182, front contact d of relay R7, wire 184, terminal b of unit 54, and through the winding of relay SSR to terminal N of the battery. Accordingly, as previously described, relay SSR will have the effect of interrupting the input circuit to storage unit 6i) and, by simultaneously closing its front contacts b and c, will commence the adjustment cycle of unit 54 for correcting the average value signal of Rh at potentiometer 66 in accordance with the valid measured value signal of Rt of the single car. Inasmuch as the operation of unit 54 was described hereinabove, it will not be repeated. However, it is reiterated that the operation of the apparatus of unit 54 is initiated when and only when relay SSR becornes energized.

With relay SSR now energized, the previously-traced -first stick :circuit for relay R8, which includes front contact e of relay SSR and its own front contact d, is completed. At the same time back contact d of relay SSR included in both the pickup and rst and second stick circuits for relay R7 is opened. Relay R7 will, therefore, become deenergized, but due to its resistor and capacitor shunt the opening of front contact d of relay R7 ld will be momentarily delayed for a time sufficient to allow the previously-traced stick circuit for relay SSR to be completed. in this way, the continued energization of relay SSR is assured.

The eventual opening of front contact c of relay R7 interrupts the pickup circuit for relay R8. This however, has no effect since relay R8 is maintained energized over its first stick circuit, just described. When relay R7 releases its front contact e, it opens the second stick circuit for relay PSR. Both stick circuits for relay PSR are now interrupted and it is deenergized and releases, thereby restoring the apparatus of storage unit 18 to its initial condition to make it available for further storage. With relay PSR now deenergized, its front contact c will open, thereby further opening the energizing circuit for relay SSR which was initially opened at front contact d of relay R7. However, this will have no effect on relay SSR since it is maintained energized over its stick circuit controlled through relay R9 by relay DR as long as the apparatus of unit 54 is in its adjustment cycle.

Following the adjustment of the wiper of potentiometer 66, relay SSR becomes deenergized and thereby prepares unit 60 to accept another signal for storage. As front contact e of relay SSR opens, the stick circuit for relay RS will be interrupted thus causing relay R8 to become deenergized.

When the wheels of the car clear track section MRZT, relay GEC becomes deenergiz-ed and, by opening its front contact b, completely opens the pickup circuit for relay SSR. It will be noted that with relays R8 and GEC deenergized, the apparatus shown in the drawings assumes the condition it normally assumes when the stretch is vacant.

While the above description relates only to the manner in which the running average value signal of Rt of a car in the heavy weight group is established, it will be understood that adjustment of the stored average value signals of Rt of cars in the light and medium weight groups is accomplished in an entirely similar manner.

Should a cut comprise more than one car, it is desirable for the reasons hereinabove mentioned to prevent it from affecting the potentiometer settings. Generally speaking, the number of cars in a cut can be determined by counting axles. For example, in the United States a single car usually has four axles, and any cut having more than four axles can be assumed to be a multiple car cut. Obviously, the apparatus of our invention can be constructed for any number of axles on a single car. However, for purposes of illustration, United States practice will be assumed. It is apparent that the operating sequence of the counting circuit up to and including the departure of the fourth wheel of a multiple car cut from the location of unit 4t) is identical to the operation of the system for a single car cut. The effect that multiple car cuts have on the apparatus embodying our invention will now be described.

The incidence of the fifth and sixth wheels of a multiple car cut on contact member 4Z will cause relay R5 to become energized for the third time, as is obvious from the chart of FIG. 2 and the previous description. With relay R5 again energized, the above-traced second stick circuit for relay R7 will be interrupted at back contact e of relay R5 and, accordingly, relay R7 will become deenergized. With relay R7 deenergized, its front contact c in the energizing circuit of relay R8 shortly opens. Further, the opening of front contact e of relay R7 will ilrsterrupt the above-traced second stick circuit for relay Relay R5 will remain energized only for the brief period the sixth wheel of the cut is being weighed. During this time, the previously-traced second stick circuit for relay R8 including its own front contact d and front contact f of relay R5 is completed. Since energization of relay R8 continues, the first stick circuit for relay PSR remains interrupted and relay PSR becomes deenergized, As the sixth wheel releases contact member 42, relay R again becomes deenergized and returns its armature to its normal position. Relay R8 will, at the same time, become deenergized due to front contact f of relay R5 being opened. As diagramatically shown in FIG. 2, relays R2 through R8 are deenergized, and their contacts are returned to their normal positions subsequent to movement of the sixth axle of the cut over Weight determining unit 46.

Once it has been established that a multiple car cut is traversing the stretch of track, that is, by having counted six axles, continued operation of the counting circuit relays in response to successive wheels of the cut is obviously unnecessary. Accordingly, it is desirable to interrupt the operation of the counting circuit after the weighing of the sixth wheel. In the present embodiment of our invention, the slow pickup relay R1 is illustrated as the means for concluding the counting sequence. Specifically, it can be seen, from FIG. 2, that relays R5 and R8 are energized concurrently only during the influence of the sixth wheel on the weight determining unit. At this time, the above-traced circuit for relay R1 including front contacts a, respectively, of relays R5 and RS will be completed. Relay R1 will accordingly become energized and shortly pickup.

When relay R1 picks up, the circuit for energizing relay PSR is interrupted at open back Contact b of relay R1; the energizing circuit for relay R2 is interrupted at open back contact c of relay R1; and the energizing circuits for relays R3, R4 and R5 are interrupted at open back Contact d of relay R1. Further, relay R1 will remain energized over its stick circuit previously traced including back contact a of relay GEC.

The continued downgrade movement of the multiple car cut will cause relay GEC to become energized, as above described. The energized condition of relay GEC does not effect energization of relay SSR as in the case of a single car cut, due to the fact that relays R7 and PSR are both deenergized prior to the end-of-cut indication. It can be seen, therefore, that by preventing relay SSR from energizing, any adjustment of the stored average value signals of Rt is precluded.

Also when relay GEC becomes energized, the stick circuit for relay R1 is interrupted, causing it to become deenergized. Under these conditions, it is apparent that the relays controlled by the contacts of relay Rl will again be prepared to distinguish between single and multiple car cuts.

As previously mentioned, it is contemplated to use the stored average value signals of Rt in order to control the speeds of all multiple car cuts and those single car cuts which fail to display acceptable rolling resistance characteristics. The use of these stored signals forms no part of our present invention, and reference is again made to our prior Patent 2,977,462, for a description of the apparatus connected to the wipers of potentiometers 66, 63 and 70.

From the foregoing description it is clear that speed control apparatus embodying our invention will have the advantage of being able to more accurately approximate the speed at which a multiple car cut should couple to a car already standing on its classification track.

Also, cuts are handled according to their weight group either when their rollability factors can not be determined or when they comprise more than one car. The stored average value signals act, in effect, as a barometer of present temperature and weather conditions due to the fact that they will be automatically and periodically adjusted during all seasons. Also, adjustment of the selected stored average value signal is permitted only when measured value signals satisfy requirements attesting to their reliability and accuracy.

Although we have herein shown and described only one form of apparatus embodying our invention, it is understood that various Changes and modifications may l be made therein within the scope of the appended Claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim l. In a railroad classification yard system including signal generating means for measuring the rolling resistance of moving cuts of railroad cars during their travel over a predetermined track section in said yard, a track device located within said section and recurringly operated from a normal to an actuated condition in response to successive wheels of cuts coming into proximity therewith; a group of normally deenergized relays each having first and second position contacts closed according as it is deenergized or energized, and including first, second, third, and fourth relays; means controlled by said device for energizing said first relay one time for every two successive wheels of a cut operating said device, means including first position contacts of said third and fourth relays and a second position contact of said first relay for energizing said second relay during the first operation of said first relay, means including first position contacts of said first and fourth relays and a second position contact of said second relay for holding said second relay energized after said first relay becomes deenergized after its first operation, means including a first position contact of said first relay and a second position contact of said second relay for energizing said third relay after said first relay becomes deenergized after its rst operation, means including a second position contact of said third relay and a first position contact of said fourth relay for holding said third relay energized, the second operation of said first relay opening the circuit for holding said second relay, means including said second position contact of said third relay and a first position contact of said first relay for continuing to hold said third relay energized after said first relay becomes deenergized after its second operation, means including a second position contact of said third relay and first position contacts of said first and second relays for energizing said fourth relay after said second operation of said first relay, the operation of said first relay for the third time opening said circuit continuing to hold said third relay energized, means including second position contacts of said rst and fourth relays for holding said fourth relay energized during the third operation of said first relay, means including said last-mentioned second position contact of said first relay for deenergizing said fourth relay after said first relay becomes deenergized after its third operation, whereby after the third operation of said first relay the contacts of the relays in said group assume their first positions, averaging apparatus having connections with said signal generating means during occupancy of said section for producing a variable value signal representative substantially of the average value of a plurality of rolling resistance signals and operable to a first or to a second condition according as it is not or is adjusting the value of the signal produced thereby, detecting means for detecting when a cut leaves the location of said device, and means for actuating said averaging apparatus to its second condition controlled jointly by said detecting means when a particular cut leaves said location and by a second position contact of said third relay when and only when said particular cut causes only two operations of said first relay.

2. A control system in a railway classification yard having a stretch of track including a track section over which cuts of railway cars travel while proceeding to assigned storage tracks, said system comprising, in combination, means for generating a signal the representative of the rolling resistance of each cut moving over said section, a storage unit connected with said signal generating means when said section is occupied and including a storage completion relay having first and second position contacts closed according as it is not or is energized, validity detecting means connected with said signal generating means when said section is occupied for determining whether each of said rolling resistance signals meets or fails to meet preselected criteria, means controlled by said validity detecting means for energizing said storage completion relay when and only when each of said rolling resistance signals meets said criteria, an averaging device connected with said storage unit when said storage completion relay is energized for producing an adjustable signal proportional substantially to the average value of a plurality of said rolling resistance signals, said averaging device normally having a first condition and actuable to a second condition in which it commences to adjust the signal produced thereby in accordance with each of said rolling resistance signals, proximity detecting means operatively connected with said section at a predetermined point for recurringly operating from a normal to an actuated condition in response to successive wheels of a cut coming into proximity therewith; a group of normally deenergized relays each having first and second position contacts closed according as it is deenergized or energized, and including first, second, third, and fourth relays; means controlled by said proximity detecting means for energizing said first relay during the interval even-numbered wheels of a cut operate said proximity detecting means, means including first position contacts of said third and fourth relays and a second position contact of said first relay for energizing said second relay during the first operation of said first relay, means including first position contacts of said first and fourth relays and second position contacts of said second relay and storage completion relay for holding said second relay energized after said first relay becomes deenergized after its first operation, means including a first position contact of said first relay and a second position contact of said second relay for energizing said third relay after said first relay becomes deenergized after its first operation, means including second position contacts of said third relay and said storage completion relay for holding said storage completion relay energized, means including a second position contact of said third relay and a first position contact of said fourth relay for holding said third relay energized, said first relay during its second operation opening the circuit for holding said second relay, means including said second position contact of said third relay and a first position contact of said first relay for continuing to hold said third relay energized after said first relay becomes deenergized after its second operation, means including a second position contact of said third relay and first position contacts of said first and second relays for energizing said fourth relay after the second operation of said first relay, said first relay during its third operation opening the circuit continuing to hold said third relay energized, means including second position contacts of said first and fourth relays for holding said fourth relay energized during the third operation of said first relay, means including said last-mentioned second position contact of said first relay for deenergizing said fourth relay after said first relay becomes deenergized after its third operation, whereby after the third operation of said first relay the contacts of the relays in said group assume their first positions, departure detecting means for determining when a cut leaves said predetermined point on said section, and means for actuating said averaging device to its second condition jointly controlled by said detecting means when a particular cut leaves said predetermined point and by a second position contact of said storage completion relay and by a second position contact of said third relay, whereby adjustment of said averaging device signal occurs when and only when a particular cut causes only two operations of said first relay.

3. In a railway classification yard control system, means for generating a signal in accordance with the rolling resistance of moving cuts of railway cars during their travel over a preselected track section in the yard, a first storage unit including a first storage completion relay, validity detecting means for determining whether each of said rolling resistance signals meets or fails to meet preselected criteria, means for connecting said signal generating means with said storage unit and said validity detecting means when said section is occupied, means controlled by said validity detecting means for energizing said first storage completion relay when and only when said rolling resistance signals meet said criteria, a second storage unit including a second storage completion relay, means controlled by said first storage completion relay when energized for connecting said first and second storage units whereby the signal stored in said first unit is transferred to said second unit for storage, said first storage completion relay when energized partially preparing a circuit for operating said second storage completion relay, an averaging means for producing an adjustable signal proportional substantially to the average value of a plurality of said rolling resistance signals, means controlled by said second storage completion relay when energized for connecting said second storage unit with said averaging means, said averaging means normally having a first condition and actuable to a second condition when said second storage completion relay is energized in which it commences to adjust the signal produced thereby, proximity detecting means having connections with said section at a predetermined point for recurringly operating from a normal to an actuated condition in response to successive wheels of a cut coming into proximity therewith; a group of normally deenergized relays including rst, second, third, and fourth relays, means having connections with said proximity detector means for operating said first relay during the interval even-numbered wheels of a cut actuate said proximity detecting means, the first operation of said first relay closing a circuit for operating said second relay, the operation of said second relay closing a circuit for holding said second relay, the deenergization of said first relay after its first operation closing a circuit for operating said third relay; the operation of said third relay closing a circuit for holding energized said first storage completion relay, closing a first circuit for holding said third relay, opening the circuit for operating said second relay, and further preparing the circuit for operating said second storage completion relay; the recperation of said first relay opening the holding circuit for said second relay to deenergize said second relay, the deenergization of said first relay after its second operation ciosing a second circuit for holding said third relay and a circuit for operating said fourth relay, the operation of said fourth relay opening the first circuit holding said third relay and the circuit for operating said second relay; the third operation of said first relay opening the second circuit holding said third relay to deenergize said third relay, opening the circuit for operating said fourth relay, and simultaneously closing a circuit for holding said fourth relay; the deenergization of said third relay after the third operation of said first relay opening the holding circuit to deenergize said first storage completion relay; the deenergization of said first relay after its third operation opening said circuit holding said fourth relay to deenergize said fourth relay, whereby following the deenergization of said fourth relay each of the relays in said group is deenergized; departure detecting means for determining when a cut leaves said predetermined point on said section, and means controlled by said departure detecting means for fully completing the operating circuit for said second storage completion relay when a particular cut no longer actuates said proximity detecting means only if said particular cut causes only two operation of said first relay.

4. A control system in a railway classification yard including a track section over which cuts of railway cars travel While proceeding toward assigned storage tracks, said system comprising, in combination, signal generating means for measuring the rolling resistance of moving cuts during their travel over said section, a track instru- 19 ment located within said section and recurringly operated from a normal to an actuated condition in response to successive wheels of cuts coming into proximity therewith, averaging apparatus for producing a continuously variable value signal representative substantially of the average value of a plurality of rolling resistance signals, and operable to a first or to a second condition according as it is not or is adjusting the value of the signal produced thereby; means for connecting said averaging apparatus with said signal generating means when said section is occupied, a group of normally deenergized relays including first, second, third and fourth relays, means having connections with said track instrument for operating said first relay during the interval successive even-numbered wheelsof a cut operate said track instrument; the first operation of said first relay closes a circuit for operating said second relay, the operation of said second relay closes a circuit for holding said second relay, the deenergization of said rst relay after its first operation closes a circuit for operating said third relay, the operation of said third relay closes a first circuit for holding said third relay and opens the circuit for operating said second relay, the reoperation of said first relay opens the circuit for holding said second relay to deenergize said second relay, the deenergization of said first relay after its second operation closes a second circuit for holding said third relay and a circuit for operating said fourth relay, the operation of said fourth relay opens the first circuit holding said third relay and the circuit for operating said second relay; the third operation of said first relay opens the second circuit holding said third relay to deenergize said third relay, opens the circuit for operating said fourth relay, and simultaneously closes a circuit for holding said fourth relay, whereby said first and fourth relays are operated concurrently; a circuit opening relay operated jointly by said first and fourth relays during their concurrent operation for interrupting said means for operating said first relay, the operation of said circuit opening relay closes a holding circuit for itself thereby allowing only three operations of said first relay per cut, the deenergization of said first relay after its third operation opens said circuit holding said fourth relay to deenergize said fourth relay whereby after the deenergization of said fourth relay following the deenergization of said first relay after its third operation each of the relays in said group is deenergized, departure detecting means for determining when a cut leaves the predetermined point on said section, means for actuating said averaging apparatus to its second condition controlled jointly by said departure detecting means when a particular cut leaves said section and by said third relay provided said particular cut causes only two operations of said first relay, and means controlled by said departure detecting means when a cut leaves said predetermined point on said section for opening the circuit holding said circuit opening relay.

References Cited by the Examiner UNITED STATES PATENTS 2,914,750 11/1959 Cook 328-121 2,977,462 3/1961 Utt et al 246-182 3,054,892 9/1962 Mowery 246-77 X 3,056,022 9/1962 Phelps 246-182 3,091,688 5/1963 COOk 246-182 FOREIGN PATENTS 811,821 4/ 1959 Great Britain.

OTHER REFERENCES An article titled: Automation for Freight Yards, by A. V. Dasburg, appearing on pp. 986-990 in the November 1955 issue of Electrical Engineering.

ARTHUR L. LA POINT, Primary Examiner.

JAMES S. SHANK, LEO QUACKENBUSH, EUGENE G. BOTZ, Examiners.

L. I. LEoNNIG, s. T. KR'AWCZEWICZ,

Assistant Examiners. 

1. IN A RAILROAD CLASSIFICATION YARD SYSTEM INCLUDING SIGNAL GENERATING MEANS FOR MEASURING THE ROLLING RESISTANCE OF MOVING CUTS OF RAILROAD CARS DURING THEIR TRAVEL OVER A PREDETERMINED TRACK SECTION IN SAID YARD, A TRACK DEVICE LOCATED WITHIN SAID SECTION AND RECURRINGLY OPERATED FROM A NORMAL TO AN ACTUATED CONDITION IN RESPOSE TO SUCCESSIVE WHEELS OF CUTS COMING INTO PROXIMITY THEREWITH; A GROUP OF NORMALLY DEENERGIZED RELAYS EACH HAVING FIRST AND SECOND POSITION CONTACTS CLOSED ACCORDING AS IT IS DEENERGIZED OR ENERGIZED, AND INCLUDING FIRST, SECOND, THIRD, AND FOURTH RELAYS; MEANS CONTROLLED BY SAID DEVICE FOR ENERGIZING SAID FIRST RELAY ONE TIME FOR EVERY TWO SUCCESSIVE WHEELS OF A CUT OPERATING SAID DEVICE, MEANS INCLUDING FIRST POSITION CONTACTS OF SAID THIRD AND FOURTH RELAYS AND A SECOND POSITION CONTACT OF SAID FIRST RELAY FOR ENERGIZING SAID SECOND RELAY DURING THE FIRST OPERATION OF SAID FIRST RELAY, MEANS INCLUDING FIRST POSITION CONTACTS OF SAID FIRST AND FOURTH RELAYS AND A SECOND POSITION CONTACT OF SAID SECOND RELAY FOR HOLDING SAID SECOND RELAY ENERGIZED AFTER SAID FIRST RELAY BECOMES DEENERGIZED AFTER ITS FIRST OPERATION, MEANS INCLUDING A FIRST POSITION CONTACT OF SAID FIRST RELAY AND A SECOND POSITION CONTACT OF SAID SECOND RELAY FOR ENERGIZING SAID THIRD RELAY AFTER SAID FIRST RELAY BECOMES DEENERGIZED AFTER ITS FIRST OPERATION, MEANS INCLUDING A SECOND POSITION CONTACT OF SAID THIRD RELAY AND A FIRST POSITION CONTACT OF SAID FOURTH RELAY FOR HOLDING SAID THIRD RELAY ENERGIZED, THE SECOND OPERATION OF SAID FIRST RELAY OPENING THE CIRCUIT FOR HOLDING SAID SECOND RELAY, MEANS INCLUDING SAID SECOND POSITION CONTACT OF SAID THIRD RELAY AND A FIRST POSITION CONTACT OF SAID FIRST RELAY FOR CONTINUING TO HOLD SAID THIRD RELAY ENERGIZED AFTER SAID FIRST RELAY BECOMES DEENERGIZED AFTER ITS SECOND OPERATION, MEANS INCLUDING A SECOND POSITION CONTACT OF SAID THIRD RELAY AND FIRST POSITION CONTACTS OF SAID FIRST AND SECOND RELAYS FOR ENERGIZING SAID FOURTH RELAY AFTER SAID SECOND OPERATION OF SAID FIRST RELAY, THE OPERATION OF SAID FIRST RELAY FOR THE THIRD TIME OPENING SAID CIRCUIT CONTINUING TO HOLD SAID THIRD RELAY ENERGIZED, MEANS INCLUDING SECOND POSITION CONTACTS OF SAID FIRST AND FOURTH RELAYS FOR HOLDING SAID FOURTH RELAY ENERGIZED DURING THE THIRD OPERATION OF SAID FIRST RELAY, MEANS INCLUDING SAID LAST-MENTIONED SECOND POSITION CONTACT OF SAID FIRST RELAY FOR DEENERGIZED SAID FOURTH RELAY AFTER SAID FIRST RELAY BECOMES DEENERGIZED AFTER ITS THIRD OPERATION, WHEREBY AFTER THE THIRD OPERATION OF SAID FIRST RELAY THE CONTACTS OF THE RELAYS IN SAID GROUP ASSUME THEIR FIRST POSITIONS, AVERAGING APPARATUS HAVING CONNECTIONS WITH SAID SIGNAL GENERATING MEANS DURING OCCUPANCY OF SAID SECTION FOR PRODUCING A VARIABLE VALUE SIGNAL REPRESENTATIVE SUBSTANTIALLY OF THE AVERAGE VALUE OF A PLURALITY OF ROLLING RESISTANCE SIGNALS AND OPERABLE TO A FIRST OR TO A SECOND CONDITION ACCORDING AS IT IS NOT OR IS ADJUSTING THE VALUE OF THE SIGNAL PRODUCED THEREBY, DETECTING MEANS FOR DETECTING WHEN A CUT LEAVES THE LOCATION OF SAID DEVICE, AND MEANS FOR ACTUATING SAID AVERAGING APPARATUS TO ITS SECOND CONDITION CONTROLLED JOINTLY BY SAID DETECTING MEANS WHEN A PARTICULAR CUT LEAVES SAID LOCATION AND BY A SECOND POSITION CONTACT OF SAID THIRD RELAY WHEN AND ONLY WHEN SAID PARTICULAR CUT CAUSES ONLY TWO OPERATIONS OF SAID FIRST RELAY. 